Abstract: In order to further study the distribution of residual strain in aortic arch, the open angles of aorta of four rabbits were measured respectively in the experiment. And the data was analysed by combining the method of analysis on arterial walls and the techology of image measuring. The distributions of open angle were obtained. The experiment has shown that the open angle is varied with the location along aortic length, the variation in bending section is greater than that in straight section and it is possible to treat it as an constant; according to the distribution and variation in different directions along the aortic ring, it also has shown that the open angle doesn't vary with the location in the aortic ring, that is to say, residual strain in arterial wall is even.